The primary objective of this project is to study the co-occurrence of stuttering and phonological disorders in young children. It is hypothesized that children who stutter but evidence normal phonological development: (1) stutter because of a disparity between speech rate performance and speech rate ability; and (2) evidence sound/syllable repetitions containing appropriate CV or VC transitions. In contrast, children who stutter and have co-existing phonological disorders: (1) stutter because of difficulties controlling, correctly producing and stabilizing speech; and (2) evidence sound/syllable repetitions with missing or inappropriate CV or VC transitions. Subjects will be 120 children, 3-7 years of age, in four age-and sex-matched groups of stutterers and nonstutterers, with and without co-existing phonological disorders. Acoustic and perceptual data from recordings of the children conversing with their mothers and naming pictures will be used to answer the following questions: (1) do the four groups differ in speaking and/or diadochokinetic rate? (2) do the four groups differ in frequency of missing or inappropriate transitions during sound/syllable repetitions and/or ability to initiate phonation of sound prolongations? (3) do the two groups of stutterers differ in frequency of sound/syllable and/or monosyllabic word repetitions or in percentage of stutterings that are sound prolongations? and (4) are there statistical relationships between speech and diadochokinetic rates, frequency/nature of speech disfluencies, percentage of sounds produced correctly and the frequency and nature of the phonological processes evidenced among the four groups? Findings are intended to: (1) clarify relationships between disordered phonology and stuttering in children; (2) pinpoint factors contributing to stuttering of children with normal and disordered phonology; and (3) identify perceptual and acoustic indexes of children's "atypical" and "typical" disfluencies as well as promising areas of clinical management.